As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems typically utilize a display device to provide visual output related to operations occurring within and/or being performed by the information handling system. Depending on the type of information handling system, the display device can be physically connected or affixed to the system, or may be communicatively connected to the system via one or more cables and/or intermediary components (e.g., a docking station). Some display devices include a touch sensitive input device that enables a user to provide input to the information handling system through direct interaction with the display device.
A display device including a touch sensitive display device is otherwise referred to as a touch screen display device, or simply a touch screen. As known in the art, a touch screen enables a user to provide input to, or interact with, the display device or the information handling system via touch events, which are detected by components of the touch sensitive input device at precise locations on the display screen. There are many different types of touch screen technology that use different methods of sensing touch events. Examples of touch screen technology include resistive touch screens, capacitive touch screens, surface acoustic wave (SAW) touch screens, infrared touch screens and optical touch screens.
FIG. 1 is a graphical representation of a conventional touch screen display device (or simply “touch screen”) 10 comprising a display screen active area (AA) 20 for display images, video content and/or user interface components, and a bezel 30 surrounding the display screen active area. The bezel 30 provides structural support for the touch screen components and/or attaches to a support structure housing the touch screen components. In conventional touch screen display device 10, bezel 30 comprises a relatively large width (BWL and BWR) on the left and right sides of the display screen active area (AA) 20. In some cases, the width of the bezel 30 bordering the top and bottom sides of the display screen active area (AA) 20 may be similar to, or different than, the left and right sides of the device. In some cases, the width of the bezel 30 on one or more sides of the device may range between about 3 mm and about 15 mm.
In order to sense touch events, touch screen 10 may include a touch sensitive input device comprising a touch sensor panel (or simply “touch panel”) 40, which is arranged beneath the display screen active area 20. The touch panel 40 is shown with dotted lines in FIG. 1 to show that it resides behind the display screen of the display device 10. In some cases, touch panel 40 may extend beyond the display screen active area (AA) 20, so as to avoid dead spots on or near borders of the touch screen display device 10.
FIG. 2 is a graphical representation of an exemplary touch panel 40 that may be used within the conventional touch screen display device 10 of FIG. 1. As shown in FIG. 2, touch panel 40 includes a plurality of transmit lines (or drive lines) 50 and a plurality of receive lines (or sense lines) 60. The plurality of receive 60 lines are arranged at an angle (e.g., 90°) to, and intersect with, the plurality of transmit lines 50 to form a plurality of sense nodes 70. In order to detect the presence of a finger or other object on or near one or more of the sense nodes 70, a drive signal may be supplied to one or more of the transmit lines 50 via routing traces 80/85 on the left and right sides of the touch panel 40. When a user touches a particular location on the display screen, a touch signal may be induced across one or more of the sense nodes 70 and forwarded to the touch sensitive input device via routing traces 90.
In FIG. 2, the plurality of transmit lines 50 are coupled to routing traces 80 and 85 on both the left and right sides of the touch panel 40. This type of routing configuration is referred to as a double routing trace configuration, and is commonly used in touch screen display devices, such as the touch screen 10 shown in FIG. 1. Because this type of routing configuration requires N routing traces on the left and right sides of the touch panel for N transmit lines 50, the double routing trace configuration shown in FIG. 2 consumes a significant amount of board space on either side of touch panel 40. The amount of board space consumed by the left routing traces 80, right routing traces 85 and ground ring 87 generally depends on the number (N) of transmit lines 50, and is illustrated in FIG. 2 as a left trace width (TWL) and a right trace width (TWR). In other cases (not shown), the plurality of transmit lines 50 may be coupled to routing traces (e.g., routing traces 80) on only one side of the touch panel 40 in a single routing trace configuration. However, this routing configuration still consumes a significant amount of board space by requiring N routing traces on the left (or right) side of the touch panel 40.
A current design trend in touch screen display devices is to reduce the border dimensions of such devices, and extend the active area of the display screen further out toward one or more edges of the display device. However, reducing border dimensions of touch screen display devices limits the available board space for routing traces from the touch panel of the display device.